Internal combustion engine valve gear



Feb. 7, 1967 c. B. LEACH 3,302,628

INTERNAL COMBUSTION ENGINE VALVE GEAR Filed Dec. 21, 1965 //VVE/VTOR 454/ 47 40 CZkjiah 15/02! ea/2 kazgym A Horney United States Patent 4Claims. (31. 123-90 This invention relates to internal combustion enginevalve gears.

In internal combustion engines in which the valve tappets act directlyon the rockers, the problem arises of ensuring that an automatic rotarymovement of the valve tappet (such as is commonly provided in knownmanner) and also the movements of both parts with respect to each otherare kept as free from friction as possible. A further problem which mayarise is that of guiding the rocker arm transversely of its plane ofmovement. The latter is of particular importance in those valveoperating gears in which the rocker arms are constructed as sheet metalpressings and are mounted on hemispherical bearing faces.

In an internal combustion engine valve gear according to this inventiona thrust transmission member between the valve actuator members isconstructed as a slide member which engages with one actuator memberthrough a ball and socket connection and is slidably engaged with theother actuator member.

According to a further feature of the invention, the slide member is ofmushroom shape, a part-spherical head on the mushroom forming one partof the ball and socket connection and the underside of the mushroombeing formed as a slide face and the stem serving as a lateral guide forthe slide member in a pin and slot connection therewith.

The slide member preferably guides the rocker arm transverse to itsplane of movement and is preferably non-detachably connected with oneactuator member.

The scope of the invention is defined by the appended claims; and theinvention and the method by which it is to be performed are hereinafterparticularly described with reference to the accompanying drawings inwhich:

FIGURE 1 is a vertical section through a portion of the cylinder head ofan internal combustion engine having a valve gear according to theinvention; and

FIGURE 2 is a part section elevation, to a larger scale, of a thrusttransmission member which forms part of the valve gear shown in FIGURE1.

FIGURE 1 of the drawings shows a cylinder head 14 including a cam of acamshaft (not shown), an inlet passage 11 closable by a poppet valve 12,and a liquid coolant passage 13. The valve 12 is pressed towards itsclosed position by a spring 15 one end of which abuts the cylinder head14 and the other end of which abuts a valve disc 16 which is secured onthe stem 17 of the valve 12 by frusto-conical collar members 20, 21which engage, in known manner, 'in a groove 22 on the valve stem 17.

A valve tappet 26 is mounted in a bore 25 in the cylinder head 14 and isadapted to be reciprocated axially upon rotation of the cam 10, thelatter engaging the tappet slightly eccentrically, in known manner, soas to ensure rotation of the tappet about its longitudinal axis duringoperation of the valve gear.

The reciprocatory movement of the tappet 26 is transmitted to the valve12 by means of a rocker arm 30 formed as a sheet metal stamping havingin the central portion thereof a part-spherical depression 31 in whichis an opening 32 through which extends a pin 33 the lower end of whichis press-fitted in a bore 34 in the cylinder head 14.

A member 35 of part-spherical shape and adapted to engage in thedepression 31 forms a bearing for the rocker arm 30 and is adjusted andsecured in position on the upper end of the pin 33 by means of a nut 36.One end 37 of the rocker arm 30 engages the upper end of the valve stem17 and the other end 45 of the rocker arm 30 carries a slide member 40(see also FIGURE 2) which acts as a thrust transmission member betweenthe valve tappet 26 and the rocker arm 30. The slide member 46 is ofmushroom shape, having a stem 46 With a part-spherical head 41 .adaptedto engage in the manner of a ball and socket joint with a correspondingpart-spherical socket 42 in the upper end of the valve tappet 26. Theunder-side of the head 41 of the slide member 40 is formed with a fiatslide surface 43 which engages a flat face 44 at said other end 45 ofthe rocker arm 30. The under-side of the head 41 is formed with anannular recess 47 between the slide surface 43 and the stem 46.

The stem 46 of the slide member 40 protrudes through a slot 43 in theend 45 of the rocker arm 30, the slot 48 being of sufiicient width toenable the stem 46 to move freely therein.

The socket 42 of the tappet 26 is also formed with a blind bore 49.

As shown in FIGURE 1, the end of the stem 46 is upset to form a flange5% so that the slide member 40 after being assembled with the rocker arm30 cannot become detached therefrom. This facilitates assembly of thevalve gear and also disassembly for repair or adjustment.

In the operation of the valve gear the reciprocation of the tappet 26upon rotation of the cam 10 effects oscillation of the rocker arm 30 onthe bearing member 35 to effect reciprocation of the valve 12, therelative movement between the rocker arm 30 and the tappet 26 in a planetransverse to the axis of the tappet being accommodated by relativemovement between the slide surface 43 of the slide member 40 and theslide surface 44 at the end 45 of the rocker arm, the slot 48accommodating the movement of the stem 46 during such sliding movement.The part-spherical head 41 on the slide member 46 and the similarlyshaped recess 42 on the tappet 26 permit rotation of the tappet 26during its reciprocation; and the pin and slot connection between theslide member 40 and the valve rocker 30 provides guiding of the rockerarm transverse to its plane of movement, so that rotation of the rockerarm about the pin 33 is prevented.

The annular groove 47 and the blind bore 49 act as reservoirs forlubricant, which is delivered in known manner to the rocker arm 30 andtappet 26, and thus facilitate the lubrication of the relatively movablesurfaces on the rocker arm, tappet and slide member.

It will \be seen from the foregoing description of one embodiment of theinvention that, thrust is transmitted between a reciprocatory and anoscillatory member by means of a slide member which has a ball andsocket engagement with one member and a slidable engagement with theother member.

I claim:

1. An internal combustion engine valve gear assembly, comprising acylinder head; a poppet valve with a stem mounted for reciprocation insaid head; a support pin secured in said head and carrying apart-spherical bearing at .its free end; a pressed metal valve rockermounted for oscillation on said bearing, said rocker having an aperturedpart-spherical depression engaged by said bearing and said pin extendingthrough the aperture in said depression, and one end of said rockerengaging the end of said valve stem; a valve tappet mounted forreciprocation in said head and formed with a part-spherical depressionin one end thereof; a camshaft rotatably mounted in said head andcarrying a cam Which engages the other end of said tappet; and .a slidemember of mushroom shape having a part-spherical head which engages thedepression in said tappet and has an under-face which is in slidableengagement with a complementary face on the other end of said rocker, astem which extends through a slot in said other end of the rocker, and aflange on the end of said stem whereby said slide member isnon-detachably but slida'bly connected to said rocker.

2. Valve gear for an internal combustion engine comprising areciprocable member having an end portion, an oscillating member havingan end portion facing said first named end portion and a slide memberengaging both said end portions and in thrust transmitting relationshiptherewith, said slide member and one of said end portions havingcoacting surfaces to form ball-andsocket-like engaging surfaces and saidslide member and the other of said end portions having coacting surfacesto form slidably engaging surfaces, said slide member being of generallymushroom shape and having a spherical head for engaging said one endportion and a slide face opposite said spherical 'head with a stemextending therefrom into a slot formed in said other end portion, saidslide member being non-detachably connected with said oscillatorymember.

3. Valve gear for an internal combustion engine comprising a valvetappet having a reciprocable end portion, a rocker arm having anoscillatory end portion positioned opposite said first named end portionand a 4 slide member engageable with both said end portions and adaptedto transmit thrust therebetween, .said slide member cooperating with oneof said end portions to form a ball-and-socket-like connection therewithand said slide member cooperating with the other of said end portions toform a slidable engagement therewith, said slide member being ofgenerally mushroom shape having a part-spherical head engageable with acorresponding recess in said valve tappet end, a slide face on theunderside of said head engageable With the end portion of said rockerarm and a stem extending from the underside of said slide member headthrough a slot in said rocker arm end portion to limit the slidablemotion of said slide member with respect to said rocker arm to apredetermined path.

4. Valve gear as defined in claim 3 wherein the end of said slide memberstem is flanged so as to prevent disengagement of said slide member fromsaid rocker arm slot.

References Cited by the Examiner UNITED STATES PATENTS 1,499,928 7/1924Hutt 12390 1,798,938 3/1931 Hallett 1239O 2,654,266 10/1953 Edelen74-569 X FOREIGN PATENTS 122,981 12/ 1946 Australia. 592,731 9/ 1947Great Britain.

MARK NEWMAN, Primary Examiner.

AL LAWRENCE SMITH, Examiner.

2. VALVE GEAR FOR AN INTERNAL COMBUSTION ENGINE COMPRISING ARECIPROCABLE MEMBER HAVING AN END PORTION, AN OSCILLATING MEMBER HAVINGAN END PORTION FACING SAID FIRST NAMED END PORTION AND A SLIDE MEMBERENGAGING BOTH SAID END PORTIONS AND IN THRUST TRANSMITTING RELATIONSHIPTHEREWITH, SAID SLIDE MEMBER AND ONE OF SAID END PORTIONS HAVINGCOACTING SURFACES TO FORM BALL-ANDSOCKET-LIKE ENGAGING SURFACES AND SAIDSLIDE MEMBER AND THE OTHER OF SAID END PORTIONS HAVING COACTING SURFACESTO FORM SLIDABLY ENGAGING SURFACES, SAID SLIDE MEMBER BEING OF GENERALLYMUSHROOM SHAPE AND HAVING A SPHERICAL HEAD FOR ENGAGING SAID ONE ENDPORTION AND A SLIDE FACE OPPOSITE SAID SPHERICAL HEAD WITH A STEMEXTENDING THEREFROM INTO A SLOT FORMED IN SAID OTHER END PORTION, SAIDSLIDE MEMBER BEING NON-DETACHABLY CONNECTED WITH SAID OSCILLATORYMEMBER.